Theoretical Analysis of Track Generation in 3d Method of Characteristics

Abstract

Generating the tracks to use in a 3D Method of Characteristics (MOC) simulation is not a trivial task. The method used to generate tracks has significant implications on the memory and compute requirements for a problem and the current track generation methods have shortcomings. In this study, we provide a detailed description and analysis of the current state of the art method to generate tracks for direct 3D MOC, the Modular Ray Tracing (MRT) method. Additionally, a new global method for generating tracks is presented that is generalizable to many geometries, domain decomposition schemes, and quadrature sets. The main difference between the global and modular track generation approaches is that the global approach does not require any knowledge of the underlying geometry discretization and is therefore more flexible in domain decomposing the geometry. Some considerations with memory requirements and general applicability that we and others have found are discussed